This invention relates to thermal spraying apparatus, and specifically to electric arc spray guns of the type wherein an electric arc is used to melt the forward ends of a pair of metal wires, and a stream of atomizing air is directed into the molten metal to form small droplets and propel them in a forward direction as a spray. Such spray guns are commonly referred to in the art as arc spray guns or, for brevity, "arc guns."
Although arc spray metallizing guns are well known and have been suitable for many purposes, experience has shown that they are not practical for certain tasks. For example, the spray rate of present day arc guns is such that it is too labor-intensive to use them for spraying large structures such as bridges. Metallized spraying of such structures is a very desirable technique since it is possible to spray a zinc coating which will give cathodic protection which is more effective and more durable than conventional painting of such structures.
One object of the invention is to provide an arc spray gun which is suitable for large scale projects and is capable of delivering a higher spray rate than existing devices of this type.
Another object is to provide an arc spray gun which is relatively lightweight and is easily manipulated, yet is also able to deliver a metallizing spray at a high rate.
Another object is to provide an arc spray gun which is effective, relatively uncomplicated and easily maintained.